Light-emitting element

ABSTRACT

Disclosed are a light emitting device and a method of manufacturing the same. The light emitting device includes a second electrode layer, a light emitting semiconductor layer including a second conductive semiconductor layer, an active layer, and a first conductive semiconductor layer on the second electrode layer, a reflective member spaced apart from the light emitting semiconductor layer on the second electrode layer, and a first electrode layer on the first conductive semiconductor layer.

TECHNICAL FIELD

The embodiment relates to a light emitting device.

BACKGROUND ART

Recently, various studies and researches have been carried out regardinga device employing a light emitting diode (LED) as a light emittingdevice.

The LED converts an electrical signal into light by using thecharacteristic of a compound semiconductor. The LED has the stackstructure of a first conductive semiconductor layer, an active layer,and a second conductive semiconductor layer and emits light through theactive layer as power is applied thereto. The first conductivesemiconductor layer may serve as an N-type semiconductor layer, and thesecond conductive semiconductor layer may serve as a P-typesemiconductor layer, or vice versa.

Meanwhile, in such a light emitting device, the light emitted from theactive layer is discharged through a lateral side as well as a topsurface of the light emitting device, so that light emitting efficiencymay be degraded.

DISCLOSURE Technical Problem

The embodiment provides a light emitting device having a novel structureand a method of manufacturing the same.

The embodiment provides a light emitting device capable of improvinglight efficiency in the direction of a top surface thereof and a methodof manufacturing the same.

The embodiment provides a light emitting device capable of reflectinglaterally emitted light in the direction of the top surface and a methodof manufacturing the same.

TECHNICAL SOLUTION

According to the embodiment, a light emitting device includes a secondelectrode layer, a light emitting semiconductor layer including a secondconductive semiconductor layer, an active layer, and a first conductivesemiconductor layer on the second electrode layer, a reflective memberspaced apart from the light emitting semiconductor layer on the secondelectrode layer, and a first electrode layer on the first conductivesemiconductor layer.

According to the embodiment, the light emitting device includes a secondelectrode layer, a light emitting semiconductor layer including a secondconductive semiconductor layer, an active layer, and a first conductivesemiconductor layer on the second electrode layer, and a reflectivemember at an outside of the light emitting semiconductor layer.

ADVANTAGEOUS EFFECTS

The embodiment can provide a light emitting device having a novelstructure and a method of manufacturing the same.

The embodiment can provide a light emitting device capable of improvinglight efficiency in the direction of a top surface thereof and a methodof manufacturing the same.

The embodiment can provide a light emitting device capable of reflectinglight laterally emitted in the direction of a top surface and a methodof manufacturing the same.

DESCRIPTION OF DRAWINGS

FIGS. 1 and 6 are sectional views showing a light emitting device and amethod of manufacturing the same according to a first embodiment of thepresent invention;

FIG. 7 is a sectional view showing a light emitting device according toa second embodiment of the present invention;

FIG. 8 is a plan view showing the light emitting device according to theembodiments of the present invention; and

FIG. 9 is a plan view showing the light emitting device according to theembodiments of the present invention.

BEST MODE

In the description of the embodiments, it will be understood that, whena layer (or film), a region, a pattern, or a structure is referred to asbeing “on” or “under” another substrate, another layer (or film),another region, another pad, or another pattern, it can be “directly” or“indirectly” on the other substrate, layer (or film), region, pad, orpattern, or one or more intervening layers may also be present. Such aposition of the layer has been described with reference to the drawings.

The thickness and size of each layer shown in the drawings can beexaggerated, omitted or schematically drawn for the purpose ofconvenience or clarity. In addition, the size of elements does notutterly reflect an actual size.

FIGS. 1 and 6 are sectional views showing a light emitting device and amethod of manufacturing the same according to a first embodiment of thepresent invention, and FIG. 7 is a sectional view showing a lightemitting device according to a second embodiment of the presentinvention. FIGS. 8 and 9 are a plan view showing the light emittingdevice according to the embodiments of the present invention.

Referring to FIG. 6, the light emitting device according to the firstembodiment of the present invention includes a second electrode layer70, an ohmic contact layer 60 formed on the second electrode layer 70, alight emitting semiconductor layer including a second conductivesemiconductor layer 50, an active layer 40, and a first conductivesemiconductor layer 30 formed on the ohmic contact layer 60, and a firstelectrode layer 90 formed on the first conductive semiconductor layer30. In addition, a reflective member 100 having an inclined surface isformed at a side of the light emitting semiconductor layer including thesecond conductive semiconductor layer 50, the active layer 40, and thefirst conductive semiconductor layer 30.

The first conductive semiconductor layer 30 may include a nitride-basedsemiconductor layer having N-type impurities, and the second conductivesemiconductor layer 50 may include a nitride-based semiconductor layerhaving P-type impurities. The active layer 40 may include anitride-based semiconductor layer having a multiple quantum wellstructure such that electrons are combined with holes to produce light.

The reflective member 100 may include a second conductive semiconductor,a stack structure of the second conductive semiconductor layer and theactive layer, or a stack structure of the second conductivesemiconductor layer, the active layer, and the first conductivesemiconductor layer.

In other words, the reflective member 100 may include a nitride-basedsemiconductor layer similarly to the light emitting semiconductor layer.

The reflective member 100 is provided at the side of the light emittingsemiconductor layer including the second conductive semiconductor layer50, the active layer 40, and the first conductive semiconductor layer 30while being spaced apart from the light emitting semiconductor layer.Accordingly, the reflective member 100 reflects light, which is emittedfrom the active layer 40 through a lateral side thereof, upwardly.

Therefore, light emitted from the light emitting device according to thepresent embodiment is forwarded upwardly, so that the light emittingefficiency of the light emitting device can be improved.

FIG. 7 is a sectional view showing the light emitting device accordingto the second embodiment of the present invention. The light emittingdevice according to the second embodiment is similar to the lightemitting device according to the first embodiment.

In order to improve the light emitting efficiency by the reflectivemember 100, a reflective layer 110 is formed at a lateral side of thereflective member 100. The reflective layer 110 may include gold (Ag) oraluminum (Al) representing superior reflectance.

FIGS. 8 and 9 are plan views showing the light emitting device accordingto the embodiments. The reflective member 100 is formed at a side of thelight emitting semiconductor layer including the second conductivesemiconductor layer 50, the active layer 40, and the first conductivesemiconductor layer 30 while being spaced apart from the light emittingsemiconductor layer. The reflective member 100 may be provided in theform of a dot or a fence. The reflective member 100 may surround thelight emitting semiconductor layer including the second conductivesemiconductor layer 50, the active layer 40, and the first conductivesemiconductor layer 30.

In addition, the reflective member 100 may be provided in thecombination form of the dot and the fence. For example, the reflectivemember 100 may include one of fence type reflective members shown inFIG. 9, and the dot type reflective member shown in FIG. 8.

Hereinafter, the method of manufacturing the light emitting deviceaccording to the embodiment will be described in detail with referenceto FIGS. 1 to 6.

Referring to FIG. 1, an un-doped GaN layer 20, the first conductivesemiconductor layer 30, the active layer 40, and the second conductivesemiconductor layer 50 are formed on a substrate 10. In addition, abuffer layer (not shown) may be interposed between the substrate 10 andthe un-doped GaN layer 20.

The substrate 10 may include at least one of sapphire (Al₂O₃), silicon(Si). silicon carbide (SiC), gallium arsenide (GaAs), zinc oxide (ZnO),and magnesium oxide (MgO).

The buffer layer may include a multi-layer having a stack structure suchas AlInN/GaN, InxGa_(1−x)N/GaN, orAl_(x)In_(y)Ga_(1−x−y)N/In_(x)Ga_(1−x)N/GaN. For example, the bufferlayer may be grown by injecting trimethyl-gallium (TMGa),trimethyl-indium (TMIn) and trimethyl-aluminum (TMAl) into a chambertogether with hydrogen gas and ammonia gas.

The un-doped GaN layer 20 may be grown by injecting TMGa into thechamber together with hydrogen gas and the ammonia gas.

The first conductive semiconductor layer 30 may include a nitride-basedsemiconductor layer implanted with first conductive impurity ions. Forexample, the first conductive semiconductor layer 30 may be asemiconductor layer implanted with N-type impurity ions. The firstconductive semiconductor layer 30 may be grown by injecting TMGa andsilicon nitride (SiN₄) including N-type impurities (e.g., Si) into thechamber together with hydrogen gas and ammonia gas.

Then, the active layer 40 and the second conductive semiconductor layer50 are formed on the first conductive layer 30.

The active layer 40 may have a single quantum well structure or amulti-quantum well structure. For example, the active layer 40 mayinclude a stack structure of an InGaN well layer/a GaN barrier layer.

The second conductive semiconductor layer 50 may include a nitride-basedsemiconductor layer implanted with second conductive impurity ions. Forexample, the second conductive semiconductor layer 50 may include asemiconductor layer implanted with P-type impurity ions. The secondconductive semiconductor layer 50 may be grown by injecting TMGa andbis-ethylcyclopentadienyl magnesium (EtCp₂Mg) {Mg(C₂H₅C₅H₄)₂} includingp type impurities (for example, Mg) into the chamber together withhydrogen gas and ammonia gas.

Referring to FIG. 2, the ohmic contact layer 60 and the second electrodelayer 70 are formed on the second conductive semiconductor layer 50.

The ohmic contact layer 60 may include a transparent electrode layer.For example, the ohmic contact layer 60 may include at least one of ITO,ZnO, RuO_(x), TiO_(x), and IrO_(x).

The ohmic contact layer 60 may include at least one of a reflectivelayer and an adhesive layer.

The second electrode layer 70 may include at least one of titanium (Ti),chromium (Cr), nickel (Ni), aluminum (Al), platinum (Pt), gold (Au), anda conductive substrate.

Referring to FIG. 3, the substrate 10 and the un-doped GaN layer 20 areremoved from the resultant structure of FIG. 2. If the buffer layer hasbeen formed, the buffer layer is removed.

Referring to FIG. 4, a mask 80 is formed on the first conductivesemiconductor layer 30 in the resultant structure of FIG. 3.

The stack structure of the second conductive semiconductor layer 50, theactive layer 40, and the first conductive semiconductor layer 30 isselectively etched through a dry etch process using the mask 80.

Referring to FIG. 5, after forming the light emitting semiconductorlayer including the second conductive semiconductor layer 50, the activelayer 40, and the first conductive semiconductor layer 30 in order toemit light through the etch process of FIG. 4, the reflective member 100is formed at the side of the light emitting semiconductor layer whilebeing spaced apart from the light emitting semiconductor layer.

In this case, the reflective member 100 may include a stack structure ofthe second conductive semiconductor layer, the active layer, and thefirst conductive semiconductor layer.

Referring to FIG. 6, the first electrode layer 90 is formed on the firstconductive semiconductor layer 30.

Meanwhile, as described above, the reflective layer 110 may be formed onthe surface of the reflective member 100. If the reflective layer 110 isadditionally formed, the structure of FIG. 7 is obtained.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

INDUSTRIAL APPLICABILITY

The embodiment can be adapted to a light emitting device used as a lightsource.

1-15. (canceled)
 16. A light emitting device, comprising: a secondelectrode layer; a stacked structure comprising a second conductive typesemiconductor layer on the second electrode layer, an active layer onthe second conductive type semiconductor layer, and a first conductivetype semiconductor layer on the active layer; a first electrode layer onthe first conductive type semiconductor layer; and a reflective memberspaced from a side surface of the stacked structure, wherein thereflective member comprises a dot type reflective member.
 17. The lightemitting device according to claim 16, wherein the reflective membersurrounds the stacked structure.
 18. The light emitting device accordingto claim 16, wherein the reflective member further comprises a fencetype reflective member.
 19. The light emitting device according to claim16, further comprising an ohmic contact layer on the second conductivetype semiconductor layer.
 20. The light emitting device according toclaim 19, wherein the ohmic contact layer is disposed between the secondelectrode layer and the second conductive type semiconductor layer. 21.The light emitting device according to claim 16, further comprising areflective layer disposed on a surface of the reflective member.
 22. Thelight emitting device according to claim 21, wherein the reflectivelayer comprises a metal containing Ag or Al.
 23. The light emittingdevice of claim 21, wherein the reflective layer comprises the secondconductive semiconductor layer.
 24. The light emitting device of claim21, wherein the reflective layer comprises the second semiconductorlayer and the active layer.
 25. The light emitting device of claim 21,wherein the reflective layer comprises the second conductivesemiconductor layer, an active layer, and the first conductivesemiconductor layer.
 26. The light emitting device according to claim16, wherein the reflective member comprises a first semiconductor layer,a second active layer, and a second semiconductor layer, which arestacked on each other.
 27. The light emitting device according to claim26, wherein the first semiconductor layer and the second semiconductorlayer have opposite conductive type semiconductor layers.
 28. The lightemitting device of claim 16, wherein the reflective member comprises anitride-based semiconductor layer.
 29. The light emitting device ofclaim 16, wherein a lateral side of the reflective member is an inclinedsurface.